A power supply subsystem may receive electrical energy through two or more supply rails, each specified to safely provide a maximum average current. The power supply subsystem may transform the electrical energy to power a set of regulated voltage rails used by an associated load circuit. One reason to deliver the electrical energy through multiple supply rails is to supply more total power to the load circuit than one supply rail is conventionally configured to provide. As the load circuit increases power consumption, current may increase in one or more of the supply rails. Under certain loading conditions, a conventional power supply subsystem may draw more current from one supply rail than other supply rails, leading to inefficient utilization of potentially available current. In certain scenarios, the load circuit may attempt to demand peak power that the two or more supply rails could ideally provide, however the power supply subsystem may not actually be able to supply the peak power because of inefficient utilization. In such scenarios, the load circuit may not be able to achieve proper peak performance levels because the load circuit may be forced to operate in a lower power, lower performance mode to avoid exceeding maximum supply rail specifications.
In certain configurations, each of the two or more supply rails needs to be considered as distinct and independent from the other supply rails. As a consequence, arbitrary power-on and power-off sequencing of the supply rails needs to be accommodated by the power supply subsystem and the load circuit, both of which may be required to implement additional power-on states representing suboptimal operating modes. Thus, there is a need for addressing this issue and/or other issues associated with the prior art.